Abstract
About 12 years before the Wright Brothers' success, Chuhachi Ninomiya successfully invented a model propeller aircraft by himself. Without any financial support, he was not able to fully develop his invention for human use. However, it is thought that if he was given the proper resources, he could have developed a similar design to the current aircraft. There are historical records which suggest that other inventors, such as Chuhachi Ninomiya and Alphonse Penaud, were already designing and building model aircrafts before the Wright Brothers' research began. In this research, the reasons why those other inventors did not succeed in inventing an aircraft for human use will be investigated and also the conditions necessary for them to succeed will be examined.
